Tag: M.W=200-250

Walker, James B. published the artcileInhibition of sulfhydryl enzymes by 1,1′-dithiodiformamidine, Name: Formamidine disulfide dihydrochloride, the publication is Archives of Biochemistry and Biophysics (1960), 86(No. 1), 80-4, database is CAplus and MEDLINE.

Based upon the reaction of SH groups with 1,1′-dithiodiformamidine (I), it is shown that the enzymes papain, urease, and arginineglycine transamidinase contain such groups. A mechanism for this reaction of I is proposed.

Archives of Biochemistry and Biophysics published new progress about 14807-75-1. 14807-75-1 belongs to ethers-buliding-blocks, auxiliary class Salt,Thiourea,Amine,Aliphatic hydrocarbon chain, name is Formamidine disulfide dihydrochloride, and the molecular formula is C9H6N2O2, Name: Formamidine disulfide dihydrochloride.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Furukawa, Takayuki published the artcileC-H borylation by platinum catalysis, Synthetic Route of 596819-12-4, the publication is Bulletin of the Chemical Society of Japan (2017), 90(3), 332-342, database is CAplus.

Herein, authors describe the platinum-catalyzed borylation of aromatic C-H bonds. N-Heterocyclic carbene-ligated platinum catalysts are efficient catalysts for the borylation of aromatic C(sp²)-H bonds when bis(pinacolato)diboron is used as the boron source. The most remarkable feature of these Pt catalysts is their lack of sensitivity towards the degree of steric hindrance around the C-H bonds undergoing the borylation reaction. These Pt catalysts allow for the synthesis of sterically congested 2,6-disubstituted phenylboronic esters, which are otherwise difficult to synthesize using existing C-H borylation methods. Furthermore, platinum catalysis allows for the site-selective borylation of the C-H bonds ortho to fluorine substituents in fluoroarene systems. Preliminary mechanistic studies and work towards the synthetic application of this platinum catalyzed C-H borylation process are described.

Bulletin of the Chemical Society of Japan published new progress about 596819-12-4. 596819-12-4 belongs to ethers-buliding-blocks, auxiliary class Thiophene,Boronic acid and ester,Ether,Boronate Esters,Boronic acid and ester, name is 2-(5-Methoxythiophen-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, and the molecular formula is C11H17BO3S, Synthetic Route of 596819-12-4.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Furukawa, Takayuki published the artcileC-H Functionalization at Sterically Congested Positions by the Platinum-Catalyzed Borylation of Arenes, Synthetic Route of 596819-12-4, the publication is Journal of the American Chemical Society (2015), 137(38), 12211-12214, database is CAplus and MEDLINE.

Despite significant progress in the area of C-H bond functionalization of arenes, no general method is reported for the functionalization of C-H bonds at the sterically encumbered positions of simple arenes, such as mesitylene. Herein, the authors report the development of the 1st Pt-based catalyst for C-H borylation of arenes and heteroarenes. Notably, this method exhibited high tolerance toward steric hindrance and provided rapid access to 2,6-disubstituted phenylboronic esters, valuable building blocks for further elaborations.

Journal of the American Chemical Society published new progress about 596819-12-4. 596819-12-4 belongs to ethers-buliding-blocks, auxiliary class Thiophene,Boronic acid and ester,Ether,Boronate Esters,Boronic acid and ester, name is 2-(5-Methoxythiophen-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, and the molecular formula is C11H17BO3S, Synthetic Route of 596819-12-4.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Kleybolte, Moritz E. published the artcileHigh-Molecular-Weight Bisalkoxy-Substituted Poly(para)phenylenes by Kumada Polymerization, Related Products of ethers-buliding-blocks, the publication is Macromolecules (Washington, DC, United States) (2022), 55(13), 5361-5370, database is CAplus.

Substituted poly(para)phenylenes (PPPs) are conjugated polymers with an attractive application potential in various fields of materials science. They are synthesized nearly exclusively using catalytic cross-coupling polymerization reactions based on Pd- or Ni-catalysts. Among these synthetic approaches to access alkoxy-substituted PPPs, Kumada catalyst transfer polymerization (KCTP or GRIM polymerization) would offer certain economic advantages over Suzuki-type polymerization as it relies on the utilization of a non-precious metal for catalysis. It also results in less total costs of the utilized reagents, avoiding addnl. preparative steps such as synthesis, isolation, and purification of boronic acid derivatives necessary for the Suzuki reaction. In fact, KCTP is nowadays the state-of-the-art method for the synthesis of polythiophenes. However, the application of KCTP for the synthesis of alkoxy-substituted PPPs leads to polymers with low mol. weights, limiting their practical applicability. Here, we developed a synthesis protocol that resulted in MEH-PPP with a mol. weight of M_n = 133 kg/mol and BHex-PPP with M_n = 153 kg/mol relative to polystyrene, outperforming the previous state of the art by a factor more than 5. Also, a tetra(ethylene glycol)-substituted PPP has been prepared by this procedure, with a mol. weight exceeding the previously reported results for analogous structures. Such mol. weights can be obtained in a reasonable reaction time (5 days) using low concentrations of an N-heterocyclic carbene-coordinated Ni complex. The polymerization kinetics suggested a chain-growth mechanism with a chain transfer step. The latter is caused most likely by a bimol. interaction of the Ni-species at the polymer chain ends.

Macromolecules (Washington, DC, United States) published new progress about 146370-51-6. 146370-51-6 belongs to ethers-buliding-blocks, auxiliary class Benzene,Ether, name is 1-((2-Ethylhexyl)oxy)-4-methoxybenzene, and the molecular formula is C15H24O2, Related Products of ethers-buliding-blocks.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Cao, Kangning published the artcileCatalytic Enantioselective Addition of Prochiral Radicals to Vinylpyridines, Category: ethers-buliding-blocks, the publication is Journal of the American Chemical Society (2019), 141(13), 5437-5443, database is CAplus and MEDLINE.

Pyridine, one of the most important azaarenes, is ubiquitous in functional mols. The electronic properties of pyridine were exploited to trigger asym. transformations of prochiral species as a direct approach for accessing chiral pyridine derivatives However, the full potential of this synthetic strategy for the construction of enantioenriched γ-functionalized pyridines remains untapped. Here, the authors describe the first enantioselective addition of prochiral radicals to vinylpyridines under cooperative photoredox and asym. catalysis mediated by visible light. The enantioselective reductive couplings of vinylpyridines with aldehydes, ketones, and imines were achieved by employing a chiral Bronsted acid to activate the reaction partners and provide stereocontrol via H-bonding interactions. Valuable chiral γ-secondary/tertiary hydroxyl- and amino-substituted pyridines were obtained in high yields with good to excellent enantioselectivities.

Journal of the American Chemical Society published new progress about 596819-12-4. 596819-12-4 belongs to ethers-buliding-blocks, auxiliary class Thiophene,Boronic acid and ester,Ether,Boronate Esters,Boronic acid and ester, name is 2-(5-Methoxythiophen-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, and the molecular formula is C11H17BO3S, Category: ethers-buliding-blocks.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Khoshkhoo, Mahdi Samadi published the artcileContribution of chromophores with different numbers of repeat units to overall emission of MEH-PPV: An experimental and simulation study, Formula: C15H24O2, the publication is Polymer (2013), 54(15), 4017-4029, database is CAplus.

In the present study, poly[1-methoxy-4-(2′-ethylhexyloxy)-p-phenylenevinylene] (MEH-PPV) was synthesized, modified and characterized by FTIR, NMR, GPC, UV/vis absorption, fluorescence, and mass spectroscopy. The effective conjugation length was controlled by introducing phys. and chem. defects into the chain backbone. It was observed that absorption and emission spectra of polymer chains were blue-shifted by importing structural deficiencies. Chem. defects were introduced by controlled oxidation of vinylene double bonds using m-chloroperbenzoic acid and phys. defects were induced by tuning polymer-solvent interactions (varying solvent quality). It was shown for the first time that the recorded fluorescence spectrum of MEH-PPV can be reconstructed using the emission data of oligomeric constituents and the contribution of chromophores with different numbers of repeat units to overall emission can be quantified. The effect of excitation energy on the emission pattern was also investigated. It was shown that the emission contribution of shorter chromophores to overall emission is detectable using high excitation energies. Finally, atomistic mol. dynamic (MD) simulation was used to investigate the polymer chain conformation in methanol and chloroform. The results obtained from torsional angles studies confirmed the presence of a great number of induced phys. defects in the backbone and, hence, a collapsed conformation of polymer chains in methanol. Evaluations of phys. defects along the chain proposed the average number of coplanar Ph rings of ∼5 and 14 for polymer chains in methanol and chloroform resp.

Polymer published new progress about 146370-51-6. 146370-51-6 belongs to ethers-buliding-blocks, auxiliary class Benzene,Ether, name is 1-((2-Ethylhexyl)oxy)-4-methoxybenzene, and the molecular formula is C15H24O2, Formula: C15H24O2.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Thavornsin, Nopparat published the artcileDirect synthesis of poly(p-phenyleneethynylene)s from calcium carbide, Recommanded Product: 1-((2-Ethylhexyl)oxy)-4-methoxybenzene, the publication is Polymer Chemistry (2014), 5(1), 48-52, database is CAplus.

An efficient method for the preparation of poly(p-phenyleneethynylene)s (PPEs) from direct coupling reactions between aryl diiodides and the inexpensive chem. feedstock calcium carbide was developed. A variety of PPEs can be prepared in high yields (71-93%) with the d.p. between 36 and 128, offering fluorescence quantum efficiencies in the range of 0.34-0.71.

Polymer Chemistry published new progress about 146370-51-6. 146370-51-6 belongs to ethers-buliding-blocks, auxiliary class Benzene,Ether, name is 1-((2-Ethylhexyl)oxy)-4-methoxybenzene, and the molecular formula is C18H12ClNO, Recommanded Product: 1-((2-Ethylhexyl)oxy)-4-methoxybenzene.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Wang, Hualin published the artcileSynthesis and optical properties of an alternating copolymer composed of MEHPV and 1,3,4-oxadiazole, Quality Control of 146370-51-6, the publication is Journal of Southeast University (English Edition) (2008), 24(2), 238-242, database is CAplus.

A poly (p-phenylenevinylene) (PPV) alternating copolymer, poly [(2, 5-diphenylene-1, 3, 4-oxadiazole) 44′ – vinylene-alt-2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene] (oxa-MEHPV), is synthesized by Heck coupling reaction and characterized with UV-vis, Fourier transform IR (FT-IR), ¹H-NMR and photoluminescence (PL) spectroscopy. oxa-MEHPV possesses an outstanding thermal stability and shows excellent solubility in common organic solvents such as dichloromethane, chloroform, toluene, and tetrahydrofuran(THF). The introduction of the electron-deficient 1, 3, 4-oxadiazole units into the MEH-PPV backbone also increases the electron affinities of the conjugated segment, which leads to the blue-shift of the maximum absorption wavelength and makes the polymer have a high optical band-gap energy, good electron-transporting stability and high PL quantum yield.

Journal of Southeast University (English Edition) published new progress about 146370-51-6. 146370-51-6 belongs to ethers-buliding-blocks, auxiliary class Benzene,Ether, name is 1-((2-Ethylhexyl)oxy)-4-methoxybenzene, and the molecular formula is C4H3Cl2N3, Quality Control of 146370-51-6.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Dhanure, S. K. published the artcileKinetics of oxidation of thiourea by chloramine-T and p-benzoquinone, Computed Properties of 14807-75-1, the publication is Oxidation Communications (2001), 24(3), 400-407, database is CAplus.

Kinetics of oxidation of thiourea by chloramine-T both in acid and alk. medium was studied. In acid medium, the reaction is second order in substrate, first order in oxidant and inverse fractional order in [H⁺]. In alk. medium the reaction is first order in oxidant, substrate and inverse fractional order in [OH^–]. Stoichiometric experiments reveal that these oxidation reactions are mixed reactions: the first one being the formation of disulfide and the second one in a parallel sequence giving urea and sulfate ion. A mechanism is postulated to explain the results. As a parallel study 1,4-benzoquinone was used for the oxidation of thiourea. These reactions occur with facility at pH 3-5; they are very fast below pH 3. The oxidant benzoquinone undergoes decomposition in alk. medium ruling out the possibility of any oxidation by benzoquinone of thiourea in alk. medium.

Oxidation Communications published new progress about 14807-75-1. 14807-75-1 belongs to ethers-buliding-blocks, auxiliary class Salt,Thiourea,Amine,Aliphatic hydrocarbon chain, name is Formamidine disulfide dihydrochloride, and the molecular formula is C2H8Cl2N4S2, Computed Properties of 14807-75-1.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Dhanure, S. K. published the artcileKinetics of oxidation of thiourea by chloramine-T and p-benzoquinone, COA of Formula: C2H8Cl2N4S2, the publication is Oxidation Communications (2001), 24(1), 91-98, database is CAplus.

The kinetics of oxidation of thiourea by chloramine-T both in acid and alk. medium was studied. In acid medium, the reaction is second order in substrate, first order in oxidant and inverse fractional order in H⁺. In alk. medium the reaction is first order in oxidant, first order in substrate and inverse fractional order in [OH^–]. Stoichiometric experiments reveal that these reactions are mixed: the first one being the formation of disulfide and the second one in a parallel sequence giving urea and sulfate ion. A mechanism is postulated to explain the results. As a parallel study 1,4-benzoquinone was used for the oxidation of thiourea. These reactions occur with facility at pH 3-5; they are very fast below pH 3. The oxidant benzoquinone undergoes decomposition in alk. medium ruling out the possibility of any oxidation of thiourea by benzoquinone in the alk. medium.

Oxidation Communications published new progress about 14807-75-1. 14807-75-1 belongs to ethers-buliding-blocks, auxiliary class Salt,Thiourea,Amine,Aliphatic hydrocarbon chain, name is Formamidine disulfide dihydrochloride, and the molecular formula is C2H8Cl2N4S2, COA of Formula: C2H8Cl2N4S2.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem